With the improvement of the technology, touch control panels are widely used in the daily life, and the user could control the electronic device more intuitively. In the prior arts, the structures of the touch control panel are usually resistive-type or capacitance-type. However, resistive-type or capacitance-type touch control panel are only suitable for small size touch control panels, and the manufacturing cost would be increased dramatically when applying the aforementioned types on huge size touch control panels.
Therefore, an optical coordinate input device is provided in the prior art to solve the problem of high manufacturing cost when using the resistive-type or the capacitance-type touch control panel. Please refer FIG. 1, which is a schematic diagram of the optical coordinate input device of the prior art.
In FIG. 1, the optical coordinate input device 90 includes a detection area 91, a first camera module 92, a second camera module 93, a reflective frame 94, and a processing module 95. The detection area 91 is provided for being touched by the object 96. The first camera module 92 and the second camera module 93 would emit invisible light toward the reflective frame 94, and capture the signal reflected by the reflective frame 94. If the object 96 is near or touches the detection area 91, the object 96 would shell the light image reflected by the reflective frame 94, and thus the processing module 95 could calculate the coordinate of the object 96 according to the images captured by the first camera module 92 and the second camera module 93.
However, when the optical coordinate input device of the prior art is applied in a huge size apparatus, for example over than 100 inch, it would be limited by the resolution ability to the received signal of the processing module 95 and the weak reflected signals on the diagonal line emitted by the first camera module 92 and the second camera module 93. If we want to raise the resolution ability of the processing module 95, the lens of the first camera module 92 and the second camera module 93 have to be increased to improve the image quality and the resolution ability, and that would increase the cost hugely. In addition, if a corner signals want to be amplified, the emitting strength of the first camera module 92 and the second camera module 93 could be enhanced, but that would cause the signals of the touch-points near the first camera module 92 and the second camera module 93 to be overexposed when being received. When the processing module 95 executes the touch control algorithm, the overexposed signals would cause the incorrect coordinates near the camera modules.
Therefore, an optical coordinate input device used in the huge size device has to be invented to solve the disadvantages of the prior arts.